Definition of "Jack"

Since every Jack became a gentlemanthere's many a gentle person made a Jack.

c. 1593 (date written), William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene iii]

Heere comes leane Iacke, heere comes bare-bone. How now my ſweet Creature of Bombaſt, how long is't agoe, Iacke, ſince thou ſaw'ſt thine owne Knee?

c. 1597, William Shakespeare, “The First Part of Henry the Fourth, with the Life and Death of Henry, Sirnamed Hot-spvrre”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies, London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, act II, scene iv, page 58, column 1

JACK. Well, really, Gwendolen, I must say that I think that there are lots of other much nicer names. I think Jack, for instance, a charming name.GWENDOLEN. Jack?...No, there is very little music in the name Jack, if any at all, indeed. It does not thrill. It produces absolutely no vibrations...I have known several Jacks, and they all, without exception, were more than usually plain. Besides, Jack is a notorious domesticity for John!

1895, Oscar Wilde, The Importance of Being Earnest […] , [Act I]

Before I leave, brush my teeth with a bottle of Jack.

2009, "Ke$ha" (Kesha Rose Sebert), Tik Tok (song)

Got a boy back home in Michigan / And it tastes like Jack when I'm kissing him / So I told him that I never really liked his friends / Now he's gone and he's calling me a bitch again

2017, Halsey, Ricky Reed, Justin Tranter, Rogét Chahayed, “Bad at Love”, in Hopeless Fountain Kingdom‎, performed by Halsey

When he went home on leave he rioted on a large scale—pompously. Jack ashore—with a difference—in externals only.

1899, Joseph Conrad, Heart of Darkness, section 1